Lucy Hale on Hosting the Teen Choice Awards and Shopping for Fall

Ten years in the biz, and cooler than ever! Mark, the beauty brand that's counted Ashley Greene and Lauren Conrad among its ambassadors, celebrated a decade of style with a cheerful birthday bash that featured all its fall goodies, from shimmery lipglosses to sequin skirts. Lucy Hale, the face of its latest campaign, helped commemorate the milestone in New York City—just hours after co-hosting the Teen Choice Awards!

"Oh man, it's been tiring!" she said, fresh off a flight from Sunday night's broadcast in Los Angeles. "I'm exhausted, but I'm so glad I'm able to be a part of this because I love the brand." The star, known for her flawless style on and off the red carpet, is particularly excited about the Mark's new charm necklaces, stackable bracelets, and demure rings. "I'm really into delicate jewelry right now," she said. "I used to only do statement accessories, but I think little dainty pieces are so perfect for fall."

As for her wardrobe must-haves, the Pretty Little Liar prefers sweet and simple. "When you're going back to school, it's important to keep it casual. A cool T-shirt and jeans are always a good way to go," she said. "Just dress whatever you're wearing up with some accessories and a great pair of heels, and you've got it!" Wise words, whether you're hitting a star-studded event like Lucy or just heading to homeroom.

In addition to repping Mark's cosmetics, she's also the face of the M.Powerment campaign, which works to fight domestic violence among teens. "Empowering women is something I truly believe in, and I'm very happy to have a hand in encouraging girls to be strong and unique in everything they do." Style for a cause—that's something we can all get behind.